After teaching about Author's Purpose, I give each of my students a mini candy bar. (We also go over the four purposes of writing for this activity.) I have enough purposes copied, cut out, and folded in a basket. Each student chooses a slip of paper but does not show anyone. They fold their paper on the dotted line and glue their purpose under the flap. (You have to copy the first 2 pages back to back.) They also glue the wrapper from the candy bar in the square. They then write about their candy bar based on the purpose they drew out of the basket. When everyone is finished they take turns sharing while the others try to figure out the purpose.